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Supporting Architectures above armv5tel

1,026 bytes added, 01:41, 17 December 2010
[0.2] Install an armv7 glibc and re-run the benchmark using dhrystone
===[0.2] Install an armv7 glibc and re-run the benchmark using dhrystone===
'''Requires:''' <blockquote>[http://arm.koji.fedoraproject.org/koji/buildinfo?buildID=8721 glibc binaries]</blockquote> In order for a successful glibc armv7 build, the file ''/usr/lib/rpm/redhat/rpmrc'' needs edit to use armv7 build options. Using mock; a downloaded glibc source can be rebuilt. Once finished, the binaries can then be installed locally to the system using rpm OR a local yum repository can be created enabling the use of yum. 
'''Test Result:'''
The Dhrystone (DMIPS) results never changed. The benchmark brought the same, exact number of DMIPS. Although Dhrystone does make use of C library functions and is assumed that the glibc would have effects on the program; the results proved that upgrading the glibc did not bring what's expected.
It is proven that armv7 and armv5 provide the same level of performance especially when running C library dependent programs. Why is it possible when armv7 is supposed to be faster than armv5tel? One big hint to the question is that the system tested currently is built to use an [http://en.wikipedia.org/wiki/Application_binary_interface ABI] called "softfp". Although beagleboardXM (cortex-a8)supports the "hard floating-point" ABI, The Fedora-ARM currently can't afford to waste time in recompiling the packages to support "hardfp".
 
 
ARM Floating point is a pretty big topic, provided are some links to help you understand more.
The glibc version used can be found <ul><li>[http://en.wikipedia.org/wiki/IEEE_754-2008 Standard for floating point arithmetic]</li><li>[http://www.arm.kojicom/products/processors/technologies/vector-floating-point.php ARM Floating Point]</li><li>[https://wiki.linaro.org/Linaro-arm-hardfloat arm-hardfloat wiki]</li><li>[http://gcc.fedoraprojectgnu.org/kojiwiki/buildinfo?buildID=8721 hereSoftware_floating_point Software floating point].</li></ul>
===[0.3]===
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